This project will investigate the determinants of temporal and spatial variation in child well-being in Indonesia and Malaysia: two countries at different levels of development but that have experienced rapid socioeconomic and demographic changes over the past four decades. The project will make several contributions. First, we will consider a comprehensive set of indicators of child well-being, including mortality risks, morbidity, birth weight, nutritional status, and cognitive development. Second, we will examine the contributions of community infrastructure (specifically public and private health services) and family resources (particularly maternal education) in contributing to various dimension of child well-being. Third, using similar data and methodologies, we will exploit the rich temporal and spatial variation within and between Indonesia and Malaysia in child well-being, level of socioeconomic development, and degree of health infrastructure. The experiences of these countries over the last several decades account for a large fraction of the range of socioeconomic development levels observed in the world today. Our project will generate results of considerable generalizability with respect to the effects of family and community characteristics on child health. The project will also explore issues regarding community data quality, measurement of community-level effects, and the meaning of community in the context of the analyses of child well-being.